First the federal government audited Chipotle outlets in Minnesota and found hundreds of employees were illegal aliens. Next, the process was repeated in the Washington, D.C.-area with the same result: Chipotle was found to have hired illegal aliens. Now the feds have launched a criminal investigation into the chain’s hiring practices.

According to the Wall Street Journal, the criminal division of the U.S. Attorney for Washington, D.C., has sought documents from Chipotle regarding their employment practices. The U.S. Attorney’s office does not comment on specific cases, but a spokesperson did say the office works with ICE and other federal agencies to investigate suspected criminal offenses.

Monty Moran, the co-CEO of Chipotle, said the company is “not fully aware of the specific details about how these agencies do their work [and] will continue to work closely with government officials to answer their questions.” According to the Journal, Chipotle is “installing various new procedures for verifying employees’ immigration status” and Moran “believes [Chipotle’s] plan will address (ICE’s) concerns [and] we are working now to roll out those enhancements.”

Since the Minnesota and D.C.-area audits, Chipotle has required all outlets to use the E-Verify system to verify new hires.

Click here to read the Journal’s article on the Chipotle investigation.